Tuning and coupling means for highfrequency systems



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Filed Nov. 12, 1942 FigL h, C 5 mq\w @www o r r tu O nehm WMA www@ a n A Patentedoct. 7, 1947' TUNING AND COUPLING MEANS FOR HIGH- FREQUENCY SYSTEMS Anatole M. Gurewitsch, Schenectady, Y., asslgnor to General Electric Company, a corporation of New York y Application November 12, 1942, semi No. 465,357

11 Claims. 1

My invention relates to high frequency systems and more particularly to ultra high frequency systems of the space-resonant type.

It is important in ultra high frequency systems of the space-resonant type to provide means of v simple construction which permit readydiustment or control of the operating frequency thereof, and which obtain such control without effecting a loss of power output. In accordance with the teachings of my invention described hereinafter, I provide anew and improved tuneable ultra high frequency space-resonantI system which obviates many of the disadvantages of the prior art arrangements.

It is an object of my invention to provide a new and improved ultra high frequency spaceresonant system.

It is a further object of my invention to provide a method of operating a space-resonant system.

It is a further object of my invention to provide a new and improved ultra high frequency system of the space-resonant type the operating frequency of which is readily adjustable or controllable, and in which coupling means between various associated space-resonant cavities, or regions, is automatically and simultaneously controlled by the frequency -controlling means.

It is a still further object of my invention to provide a new and improved ultra high frequency space-resonant system which employs an electric discharge device as a central or control element and in which the coupling means between the anode-grid and grid-cathode cavities, or regions, is mechanically connected to the frequency c'ontrolling means which establishes the `natural frequency of one of the regions. I

Briefly stated, in the illustrated embodiment of my invention I provide an ultra high frequency space-resonant system which, for the purposes of illustration, is presented as comprising an ultra high frequency oscillator comprising a pair of space resonant cavities and also'com-l prising, as an element thereof, an electric discharge device 'including an anode, a cathode and a grid. A plurality of metallic or conductive cylinders are connected to the electrodes of the discharge device and` means are provided for simultaneouslycontrolling not only the natural frequency of at least one of the cavities but also for controlling the position of the coupling means so that the coupling means automatically assumes the optimum position for each operating frequency.

For a better understanding of my invention,

2 reference may be had to the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims. Fig. 1 diagrammatically illustrates -an overall side view of an ultra high frequency oscillator of the space-resonant type embodying my invention. Fig. 2 is a partial crosssectional plan view of the oscillator, and Figs. 3a and 3b, considered jointly, are a cross-sectional side view of the high frequency space-resonant oscillator showing the adjustable tuning and coupling means. Fig. 4 represents an alternative arrangement for the coupling means which may be employed in carrying out my invention.

Referring now to Fig. 1 of the accompanying' drawing, I have there illustrated my invention as applied to an ultra high frequency space-resonant system, such as an ultra high frequency oscillator, which may be arranged in a compact and readily adaptable form mounted upon a base plate I which supports the space-resonant cavities generally identified at 2. As a means for tuning or controlling the operating frequency of the oscillator, I may employ any suitable adjusting means as for example a Vernier adjustment means 3.

A better appreciation of the system may be had by referring to Figs. 2 and 3a jointly. As a central control element of the system, I may employ an electric discharge device 4 which may take the form of that ultrahigh frequency discharge device disclosed and claimed in the copending patent application Serial No. $6,633 of James E. Beggs, filed March 28, 1942, and which is assigned to the assignee of the present application. This discharge device is peculiarly adapted for the utilization of ultra high frequency energy and comprises an anode 5, a grid 6 and a thermionic cathode 1 having its emissive surface in proximity to the grid 6. Connections to the anode 5, grid 6 and cathode 1 are provided for use as high frequency terminals and which may comprise discs 8, 9 and l0 having-a stepwise configuration, as illustrated, to facilitate connection of high frequency means thereto and which will be described presently. Of course, it is to be appreciated that the electrodes of the discharge device 4 are enclosed or sealed hermetically, the discs 8, 9 and I0 being maintained in spaced relation by means of vitreous or glass cylinders Il and I2 which are sealed t0 these discs. device 4 may also be provided with a socket I3 having contact pins I4l1`, inclusive. Contact pins I4 and I5 may be employed as means for impressing@ unidirectional potential on cathode The discharge 1, and contact pins I8 and I1 may be employed l as terminals for supplying unidirectional current grid-cathode circuits of the discharge device 4, I

employ a plurality of conductive members which may take the form ofthree concentric or coaxial metallic or conductive cylinders I8, I9 and 28. Cylinders I8 and I9 deilne the anode-grid cavity or region, and cylinders I9 and 20 define the gridcathode cavity or region. Cathode 1 and more particularly its terminal comprising disc III is con-l nected to cylinder 20 by means of a plurality of resilient contact fingers 2|, and in like manner grid 6 or its associated disc terminal 9 is connected to the cylinder I9 by means of a plurality of resilient fingers 22. In addition to affording electrical connection between the respective elements of the system, fingers 2l and 22 also serve to position firmly the electric discharge device 4 within th'e assembly. In order to form a further axial support for the discharge device 4, I employ an annular metallic ring 23 which is supported by a shoulder of a cylinder 24 and which also engages socket I3 for the discharge device 4.

A suitable operating voltage, such as a unidirectional voltage, may be impressed across anode and cathode 'I by circuit connections which may assume the form of an anode connecting rod 25 and a cathode connecting rod 26 which is connected to either contact pin I4 or I5. Anode rod 25 may be centrally positioned within cylinder I8 by means of an end insulator 21 and may be connected to anode 5 by a metallic adaptor 28, the latter being tapered to firmly engage the inner surface at one end ci' cylinder I 8.

Due to the tendency to produce coupling between cylinder I8 and anode rod 25, I employ f suitable lters 29 and 30 which may take the form'of hollow `metallic sleeves having a wave length, such as a' quarter wave length of the operating frequency of the device, or in the vicinity thereof, to prohibit or restrict the transmission of high frequency energy within the region defined by the surface of anode rod 25 and the inner surface of cylinder I8.

In like manner, in order to prevent the dissipation of electromagnetic energy from the enclosure for the system as a whole and particularly through the cylinder 24, I may employ a folded filter or choke 3|, such as that disclosed and claimed in my copending patent application Serial No. 452,946, filed July 30, 1942, and which is assigned to the assignee of the present application. The filter 3| may be supported by a spacing insulator 32 and a transverse metallic wall 33.

I provide means for tuning or controlling th'e natural frequency of the space resonant regions or cavities. These tuning means may take the form of axially adjustable end walls or plungers associated with the respective cavities. For example, the anode-'grid cavity may be provided with an adjustable plunger 34 which engages the outer surface of cylinder vIii and the inner surface of cylinder I9 and which may be positioned or adjusted by any suitable mechanical expedient such as connecting rods 35 and 3B. Plunger 34, of course, is slidable along these latter mentioned surfaces and the position of the plunger determines the natural frequency 0f the anode-grid space-resonant cavityV 'or region,

Energy may be extracted from the space-resonant regions, as for example from the anode-grid cavity. by electrode means which may assume the fdrm of a loop 31 which constitutes an extension of an inner conductor 38 of the concentric transmission line comprising the inner conductor 33 and outer conductor 39 which may be terminated in a socket 40, shown in Figs. l and 4, to facilitate connection to an external utilization circuit.

In likemanner, I provide a plunger 4I for controlling the axial dimension of the grid-cathodeI space resonant region and this plunger may also be controlled by any suitable mechanical expedient such' as a pair of actuating rods 42 and 43 which with rods 35 and 36 are connected to a transversing stud 44 which rides upon a threaded rod 45 connected to the vernier adjustment 3.

I provide means for simultaneously adjusting the natural frequency of one of the space-resonant regions and for controlling the position of coupling means which controls the interchange of energy between the anode-grid and the gridcathode space resonant regions. More particularly, I provide meansfor mechanically connecting th'e coupling means to the frequency controlling means. For example, cylinder I9 is provided with an axial opening or slot 46 through which an electrode coupling means, such as a probe 41, extends thereby providing coupling between the anode-grid and the grid-cathode cavities. The probe 41 xmay be mechanically supported by and positionable with plunger 4I and may be transversely adjustable, being provided with a screwthread which engages threads of a protuberance 43 formed within the hollow annular portion of plunger 4I. In this manner, the distance which the probe 41 extends into the anode-grid cavity may be readily controlled or adjusted. As a means to facilitate external adjustment of the position of probe 41, I provide a threaded cap 49 which screws into an aperture of outer cylinder 20.

In order to prevent the establishment of an undesired region of a confined electromagnetic wave and to prevent the undesired extraction of energy from the anode-grid cavitythrough slot 46, plunger 4I may be provided with a follower part 4I which serves as a cover for slot 46 and is slidable along the outer surface of cylinder I9. The part 4I', of course, is conductive, preferably formed integral with the plunger 4 I and adapted to follow it.

In like manner, the plunger 34 may also be provided with a follower (not shown) adjacent the slot 46 to prevent the transfer of electromagnetic energy from the grid-cathode cavity to the region between cylinders I8 and I9 beyond the plunger 34.

Fig. 3b indicates somewhat in detail the Vernier adjustment which may be employed to adjust the positions of plungers 34 and 4I, and may comprise a rough adjusting knurled thumb member 50 and a iner adjusting member 5I which are connected, respectively, to an outer or large diameter adjusting cylinder 52 and an' inner connecting rod which is connected lto the threaded rod 45.

In operation, upon the impression of a unidirectional voltage across anode 5 and cathode 1, the space-resonant system will oscillate at a frequency determined by the natural resonance frequency of the cavities or regions and the discharge device 4. The operating frequency is detei-mined, of course, by the position of plungers 34 and 4 I. Energy may be extracted from the system, particularly the anode-grid region, by means of loop 31 and supplied to an external or utilization circuit which is connected to the socket 40.

The feed-back of energy from the anode-grid cavity to the grid-cathode cavity is obtained principally by means of the probe 41 which constitutesl a coupling means to supply to the latter region a voltage of proper magnitude and phase to maintain the system, as a whole, in oscillation. I have found that in systems of this nature where it is desired to provide a substantial range of operating frequencies, it is also important to position the coupling means, such as the probe 4'1, for each operatingifrequency in order that the optimum coupling effect be obtained and so that power output is not sacrificed in obtaining the frequency control. cally connecting one of the frequency controlling means, such as plunger 4l, to probe 41 upon adjustment of the operating frequency the coupling means automatically assumes that position whichv produces the optimum feed-back or coupling between the anode-grid and the grid-cathode cavities or regions.

It will be noted that plungers 34 and 4l are both connected to the transversing stud 44 through connecting rods 35, 36 and 42, 43. Consequently, upon actuation of the Vernier adjustment both of these plungers will be actuated, thereby concurrently and simultaneously controlling the dimensions of the anode-grid and the grid-cathode cavities and simultaneously controlling the natural frequencies thereof.

While in the embodiment of my invention illus trated in Fig. 3a Iv have shown the coupling means as comprising a probe 41, it- Will be appreciated by those skilled in the art that the coupling means may assume a variety of configurations and that my invention is not limited to the particular coupling means illustrated. For example, in Fig. 4 I have shown an alternative form of the coupling means which may comprise a loop 53 which extends through opening 46 in cylinder i9, and which is conductively connected to the inner surface of plunger 4I within the grid-cathode cavity and connected to the outer surface of plunger 4| facing the anode-grid cavity, the loop 53 extending through an opening 54 in the plunger 4l.

While I have shown and described my invention as applied to a particular system and as embodying various devices diagrammatically shown, it will be. obvious to those skilled in the art that changes and modifications may be made without departing from my invention, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of th'e United States is:

1. A high frequency system comprising an electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid, a pair of space resonators one of which is connected to the anode-grid circuit of said discharge device and the other of which is connected to the grid-cathode circuit of said device, coupling means between said resonators, and positionable means in operative relation to one of said resonators for tuning said one of said resonators said coupling means being mounted on said tuning means, whereby the position of said i comprising an electric Consequently, by mechaniy coupling means is controlled as said resonator is I discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid and being provided with externally accessible high frequency terminals, a plurality of eonductive'members connected to the electrodes of said discharge device defining anode-grid and grid-cathode space resonators, coupling means for effecting the transfer of electromagnetic` energy between said resonators, and positionable means in operative relationfto one of said resonators for tuning said one' of said resonators, said coupling means being mounted on said tuning means, whereby the position of said coupling means is controlled as said resonator is tuned.

3. A high frequency space resonant system comprising an electric discharge device` including a plurality of enclosed electrodes including an anode, a cathode and a grid, a plurality of substantiallycoaxial conductive cylinders connected respectively to said electrodes defining anodegrid and grid-cathode resonators, and a conductive plunger interposed between two of said cylinders for tuning the resonator defined therebetween and supporting an adjustable coupling means.

4. A high frequency space resonant system comprising an electric discharge device including an anode, a cathode and a grid having externally accessible high frequency terminals, a pair of coaxial conductive cylinders connected to said anode and said cathode and an intermediate conductive cylinder connected to said grid thereby defining anode-grid and grid-cathode resonators, said intermediate cylinder being provided with an opening extending axially, means for tuning one of said resonators comprising a conductive plunger adjustable axially of said system and supporting a coupling means which extends through said opening.

5. A high frequency space resonant system comprising an electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid having'externally accessible high frequency terminals, three concentric conductive cylinders connected respectively to said anode, said grid and said cathode thereby defining anode-grid and grid-cathode resonators. the intermediate cylinder connected to said grid being provided with a longitudinal slot, coupling means extending through said slot thereby providing a, path for the transfer of electromagnetic energy between said resonators, and means for tuning one of said resonators comprising an adjustable plunger mechanically connected to said coupling means.

6. A high frequency space resonant system comprising an electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid having externally accessible high frequency terminals, three coaxial conductive cylinders connected respectively to said anode, said grid and said cathode thereby defining anode-grid and grid-cathode resonators, the intermediate cylinder connected to said grid being provided with an axial opening, and means for simultaneously controlling the natural frequency of one of said resonators and for establishing the optimum coupling between the resonators comprising an axially adjustable conductive plunger interposed between two of said cylinders and supporting a *coupling means which extends through said opening.

'7. A high frequency oscillator of the spaceresonant type comprising an electric discharge 7 device including a plurality of enclosed electrodes including an anode, a cathode and a grid providedwith externally accessible high frequency figuration, 3 coaxial conductive cylinders con- ;nected respectively to said anode, said grid and said cathode thereby defining anode-grid and grid-cathode resonators, the .intermediate cylinder being provided with an axial slot, and means for simultaneously controlling the natural frequency of one of said resonators and for controlling the coupling between the anode-grid and the grid-cathode resonators comprising an axially adjustable conductive plunger provided with a coupling means which extends through said opening.

8. A high frequency system comprising an electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid, a, pair of resonators one of which is 9. A highfrequency space resonant system comprising an electric discharge device including an anode, a cathode and ,a grid having externally accessible high frequency terminals, a pair 0f coaxial conductive cylinders connected to said anode and said cathode and an intermediate condutive cylinder connected to said grid thereby dening anode-grid and grid-cathode resonators, said intermediate cylinder being provided with an opening extending axially, and means for ananas 8 electric discharge device including a plurality of enclosed electrodes including an anode, a cathode and a grid. a pair of cavity resonators one of which is connected to the anode-grid circuit of said discharge device and th'e other of which is connected to the grid-cathode circuit of said device, adjustable means for adjusting the dimensions of one of said resonators to tune said one of said resonators, and a coupler coupling said resonators together and connected to said ad- Justable means and movable in unison therewith i' whereby said adjustable means and the coupling between said resonators may be adjusted simultaneously. v

11. A high frequency system comprising an electric discharge device including a plurality 0f enclosed electrodes including an anode, a cathode land a grid, a pair of space resonators one of which is coupled with the anode-grid circuit of said device and th'e other of which is coupled withv REFERENCES CITED The following references are of record in the ille of this patent:

` UNITED STATES PATENTS tuning the grid-cath'ode resonator comprising a Number v Name Date conductive plunger adjustable axially the dimenip 2,280,824 Hansen et al. Apr. 28, 1942 sion of said system and supporting a coupling 2,311,520 Clifford Feb. 16, 1943 means which extends through said opening, said 2,283,895 Mouromtseif et al. May 19, 1942 plunger being provided with a conductive follow- 2,226,653 Allerding et al Dec. 31, 1940 er which partially covers said opening. 2,169,396 Samuel Aug, 15, 1939 10. A high frequency system comprising an 2,278,210 Morton Mar. 31, 1943 Certificate of Correction Patent No. 2,428,622. October 7, 1947. l ANATOLE VM. GUREWITSCH It is hereby certified that error appears in thejprnted specification of the above numbered patent .requiring correction as follows;l Column 7, line 3, -claim 7, after frequency insert terminals of disc form having wstepwse com; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofice.

Signed and sealed this 6th day of January, A..D. 1948.

y L '1| 4 PHY, Assistant ommz'sszoner of Patents. 

